Precision timing for broadcast network

ABSTRACT

The present aspects relate to techniques of timing synchronization of audio and video (AV) data in a network. In particular, the techniques for a AV master to distribute AV data encoded with one or more time markers to a plurality of processing nodes. The one or more time markers may be indexed to a precision time protocol (PTP) time stamp used as a time reference. In one technique, the nodes extract the time markers to determine an offset value that is applied to a PLL to synchronize AV data packets at a distribution node or a processing node. In another technique the distribution node or the processing node determines the worst case path, which corresponds to a system offset value. The distribution node then reports the system offset value to the AV master, which in turn adjusts the phase based on the report.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Provisional PatentApplication No. 62/146,203 entitled “PRECISION TIMING FOR BROADCASTNETWORK” filed Apr. 10, 2015, the entire contents of which are hereinincorporated by reference.

BACKGROUND

Television broadcasting involves sending video from a broadcast facilityfor distribution to receivers in a broadcast network. Within a mediaproduction facility that sends a television broadcast, video and audiosignals from multiple sources may be managed by productions switches andthen encoded for transport to a distribution network. A long standingproblem for media broadcasting is to tune and sync frequency and phaseof a decoder at a media device (e.g., a distribution node or aprocessing node such as a video receiver) to a master media timingsource (e.g., a transmitter at the source of the media transport).Propagation delays due to electrical connections, device processing, andconductor impedance of network links contribute to phase offset atdownstream media devices. As the evolution of broadcasting progressedfrom analog to digital domain and across various protocols (e.g.,MPEG-2, Internet Protocol (IP), IPTV, Ethernet), various techniques havebeen developed to manage the frequency and phase sync. Local clockreferences, such a program clock reference (PCR) time stamp or apresentation time stamp, provide no reference to real time. Otherprotocols, such as precision time protocol (PTP), provide time stampsinfrequently, and are slow to converge on a precise phase lock due tothe low refresh rate of the time stamp values. Compounding thesepotential problems with time stamps is where multiple unique time stampsmay need to be applied independently to over a hundred audio and videofeeds, each having different clock rates and phases.

As such, an efficient method for synchronizing the frequency and phaseof devices in a media network that distributes audio and video datapackets, such as for live broadcast television programming is desirable.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

In an aspect of the disclosure, a method for timing synchronization ofaudio video (AV) data, comprising: receiving the AV data encoded withone or more time markers, wherein the one or more time markers areindexed to a precision time protocol (PTP) time stamp used as a timereference for a network; and locking phase of the AV data to align phaseof the AV data based on the one or more time markers.

In an aspect of the disclosure, a node for timing synchronization ofaudio video (AV) data, comprising: a receiver configured to receive theAV data encoded with one or more time markers, wherein the one or moretime markers are indexed to a precision time protocol (PTP) time stampused as a time reference for a network a timing module configured tolock phase of the AV data based on the one or more time markers.

In an aspect of the disclosure, a computer-readable medium storingcomputer executable code for timing synchronization of received audiovideo (AV) data encoded with one or more time markers, the one or moretime markers are indexed to a precision time protocol (PTP) time stampused as a time reference for a network, the computer readable mediacomprising code to: lock phase of the AV data to align phase of the AVbased on the one or more time markers.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a media network with a broadcastproduction facility, a remote camera, and a remote production facility.

FIG. 2 is a diagram illustrating one configuration of a node within amedia network.

FIG. 3 is a signal diagram that illustrates broadcasting a time stampand distributing timing offset values.

FIG. 4 is a flowchart of a method for precision timing of a broadcastnetwork.

FIG. 5 is a conceptual data flow diagram illustrating the data flowbetween different means/components in a media processing system fortiming synchronization.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Certain aspects of video production systems will now be presented withreference to various apparatus and methods. These apparatus and methodswill be described in the following detailed description and illustratedin the accompanying drawing by various blocks, modules, components,circuits, steps, processes, algorithms, etc. (collectively referred toas “elements”). These elements may be implemented using electronichardware, computer software, or any combination thereof. Whether suchelements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented as a “processing system” thatincludes one or more processors. Examples of processors includemicroprocessors, microcontrollers, graphics processing units (GPUs),central processing units (CPUs), application processors, digital signalprocessors (DSPs), reduced instruction set computing (RISC) processors,systems on a chip (SoC), baseband processors, field programmable gatearrays (FPGAs), programmable logic devices (PLDs), state machines, gatedlogic, discrete hardware circuits, and other suitable hardwareconfigured to perform the various functionality described throughoutthis disclosure. One or more processors in the processing system mayexecute software. Software shall be construed broadly to meaninstructions, instruction sets, code, code segments, program code,programs, subprograms, software components, applications, softwareapplications, software packages, routines, subroutines, objects,executables, threads of execution, procedures, functions, etc., whetherreferred to as software, firmware, middleware, microcode, hardwaredescription language, or otherwise.

Accordingly, in one or more example embodiments, the functions describedmay be implemented in hardware, software, or any combination thereof Ifimplemented in software, the functions may be stored on or encoded asone or more instructions or code on a computer-readable medium.Computer-readable media may include transitory or non-transitorycomputer storage media for carrying or having computer-executableinstructions or data structures stored thereon. Both transitory andnon-transitory storage media may be any available media that can beaccessed by a computer as part of the processing system. By way ofexample, and not limitation, such computer-readable media can comprise arandom-access memory (RAM), a read-only memory (ROM), an electricallyerasable programmable ROM (EEPROM), optical disk storage, magnetic diskstorage, other magnetic storage devices, combinations of theaforementioned types of computer-readable media, or any other mediumthat can be used to store computer executable code in the form ofinstructions or data structures that can be accessed by a computer.Further, when information is transferred or provided over a network oranother communications connection (either hardwired, wireless, orcombination thereof) to a computer, the computer or processing systemproperly determines the connection as a transitory or non-transitorycomputer-readable medium, depending on the particular medium. Thus, anysuch connection is properly termed a computer-readable medium.Combinations of the above should also be included within the scope ofthe computer-readable media. Non-transitory computer-readable mediaexcludes signals per se and the air interface.

Propagation delays of media packets due to electrical connections,device processing, and conductor impedance of network links and the likemay offset the phase of downstream media devices. For example, surroundsound audio media may include four or five channels that may be streamedto a downstream media device through independent paths. As such, thephase of each audio channel at arrival to a media receiver may differwhich can result in microsecond delays at the decoder in synchronizationfor one or more of the surround sound channels. In instances when audiopackets are out of sync with video packets, tuning the decoder toadvance or delay the audio may be necessary to synchronize lip movementto audio signals. To date, tuning and synchronizing the frequency andphase of a decoder at a media device has been a significant challenge intelevision broadcasting, particularly, with respect to a master mediatiming source.

The present aspects relate to a technique of timing synchronization ofpacketized audio and video (AV) data in a network. In particular, thetechnique includes distributing, at an apparatus, a packetized AV dataencoded with time markers to a plurality of processing nodes. Forexample, the apparatus may be configured as a controller, an AV masterand/or a transmitter implemented as a distributed function. Theapparatus may be a receiver for a distribution node or a processing nodefor receiving the packetized AV data. In order to accurately synchronizefrequency and phase components, one or more time markers may be indexedto a precision time protocol (PTP) time stamp used as a time reference.In some aspects, the receiver includes a phase lock loop (PLL) to lockphase of the packetized AV data. As such, the receiver may automaticallyadvance or delay one or more inputs of AV media streams.

One approach is for a media receiver (e.g., controller/encoder) todetermine the delay based on query of the network connections. The mediareceiver (e.g., controller/encoder) may determine (e.g., calculate) theworst case path (e.g., longest delay) using standard methods. Based onthe worst case path (e.g., longest delay) the receiver (e.g.,controller/encoder) may adjust the phase of one or more mediacomponents.

In some aspects, the transmitter may receive feedback from the receiverand adjust the phase of the transmitted packetized AV data. For example,a media receiver (e.g., media controller/encoder) may determine thedelay based on query of the network connections and calculate the worstcase path (e.g., longest delay) using standard methods. In turn, themedia receiver (e.g., controller/encoder) may provide the transmitter(e.g., controller/AV master) with a report that includes the worst casepath (e.g., longest delay). Based on the worst case path (e.g., longestdelay) the transmitter (e.g., controller/AV master) may adjust the phaseof one or more inputs of AV media prior to transition (e.g.,distribution). In video for example, the transmitter (e.g.,controller/AV master) may adjust to a common alignment point (e.g., areal-time based time marker aligned to line 1, pixel 1).

FIG. 1 is a diagram illustrating a media processing network 100 withbroadcast production facility 101, remote camera 102, remotedistribution node 127, processing node 128, and remote productionfacility 151. In an aspect, media processing network 100 may be a medianetwork for real-time production and broadcasting of video and audio.Media processing network 100 may include the internet 103 and hardwareconducive to internet protocol (IP). That is, aspects of Mediaprocessing network 100 may be network servers and network devicesconfigures to transmit and receive video and audio signals of variousformats. For example, in an aspect, broadcast production facility 101may receive video and audio signals of various formats. It should beappreciated that broadcast production facility 101 is not limited to IP.

As depicted in FIG. 1, broadcast production facility 101 may includeproduction switch 108, storage 110, signal processor 111, controller113, transceiver 114, timing module 115, codec 116, distribution node117, and processing node 118. Broadcast production facility 101 may be aproduction setup for a broadcast entity and may include one or moredistribution nodes (e.g., electronic devices) configured to distributemedia content to one or more distribution nodes (e.g., remote mediadevices).

Production switch 108 is a distribution node for the media processingnetwork 100 and may process over 100 inputs of AV media streams receivedfrom remote inputs. In some aspects, production switch 108 may receivean input AV media stream from remote camera 102 and route the input AVmedia stream to distribution node 117 for live broadcast content such asa for live news coverage.

Storage 110 may store digital media content. That is, in an aspect,storage 110 may be a hard disk (e.g., magnetic drive), flash memory,EEPROM, and the like configure to receive and store media content. Forexample, in some instances, remote camera 102 may pre-record mediacontent (e.g., pre-recorded news/interview) to storage 110 for laterprocessing and consumption.

Signal processor 111 may perform various corrections to the videosignals. For instance, in an aspect, controller 113 may instruct thesignal processor 111 to color correction (e.g., tone, red eyecorrection) and gamma correction.

Controller 113 may provide operator instructions to the components ofthe broadcast production facility 101. In an aspect, controller 113 maybe configured to direct certain media (e.g., audio and video) feed to aparticular destination in the media processing network 100. For example,controller 113 may instruct the production switch 108 to stream mediacontent from remote camera 102 via internet 103 to processing node 128for consumer consumption. In an aspect, controller 113 may providecontrol instructions to the timing module 115 for sending the systemoffset value to codec 116 for encoding in the video data signals.

Transceiver 114 may process layer 7 (L7 of the OSI protocol stacktypically contains the media payload) signals encoded by codec 116. Forexample, in an aspect, transceiver 114 may process L7 signals fortransmission over IP (L3 of the OSI protocol stack) for consumer devicedistribution (e.g., cable TV, RF transmission, satellite TV, etc.) andfor receiving L7 signals from the consumer device network.

Timing module 115 manages one or more time markers and time referencefor the media processing network 100, and may determine a system offsetvalue so that buffers in network devices may be set appropriately tohandle a worst case timing delay in the distributed video signals. In anaspect, timing module 115 may extract a real-time based time stamp(e.g., a PTP time stamp) from internet 103, and format the time stampfor encoding by codec 116 into the audio video data stream.

Codec 116 performs encoding of video and audio data into data packetsfor transmission over IP in the media processing network 100. In someexamples, codec 116 may encode video and audio data into non-compressed(e.g., linear pulse code modulation, pulse-density modulation, directstream digital pulse-amplitude modulation, etc.), lossless (e.g., freelossless audio codec, optimFROG, wavepak, true audio, etc.), and lossy(e.g., adaptive differential (or delta) pulse-code modulation, adaptivetransform acoustic coding, MPEG-1, MPEG-2, MPEG-3, MPEG-4, etc.).

Distribution node 117 may distribute network AV data throughout thebroadcast production facility 101 to one or more processing node(s) 118.As depicted, in an aspect, distribution node 117 may distribute mediacontent to processing node 118.

Remote distribution node 127 may feed remote processing node(s) 128 viaa direct link 142, or via internet 103 connection. Examples of remotedistribution node(s) 127 and processing node(s) 128 may include remoteproduction switches similar to production switch 108 or remote signalprocessors similar to signal processor 111.

As depicted in FIG. 1, remote camera 102 may be an IP device, configuredfor the AV feed to the broadcast production facility 101 to use IP overan Ethernet connection 140. In an aspect, remote camera 102 may beconfigured for an AV feed across links 141 and 138 via the internet 103.As with all network nodes in media processing network 100, remote camera102 may receive time stamp broadcasts from the broadcast productionfacility 101 to achieve mutual precision timing with the entire network.

Remote production facility 151 may include some or all of the samecomponents of broadcast production facility 101. For frequency and phasesyncing, either the remote production facility 151 or the broadcastproduction facility 101 may act as the AV master for broadcasting timestamps to the media processing network 100 nodes. Remote productionfacility 151 may exchange transmissions with the broadcast productionfacility 101 across an internet 103 connection via links 138, 139.Aspects of implementing the remote production facility 151 may include alive production setup on location at a sports or entertainment venue,where multiple remote cameras 102 and audio recorders may feed throughcontrollers at the remote production facility 151 and fed to broadcastproduction facility 101 for media broadcasting.

FIG. 2 is a diagram illustrating one configuration of a processing node200 within a media processing network 100. In some aspects, processingnode 200 may be an implementation of a processing node such as areceiver (e.g., distribution node 117, processing node 118) or adistribution node such as production switch 108. As depicted in FIG. 2,processing node 200 may include processor 201, decoder 202, PLL 203,receiver 204, and transmitter 205. In some aspects, processing node 200may receive at receiver 204 one or more inputs of AV media stream. Thatis, AV media data may be packetized and delivered via different paths.As such, each AV media data packet may have a different phase associatedwith a delay.

As depicted in FIG. 2, processor 201 is configured to process the AVdata input received from an upstream node. In particular, processor 201may be configured to determine the phase from one or more time markersencoded in each AV media data packet. In an aspect, processor 201 isconfigured to determine absolute phase offset values for each AV mediadata packet. In an aspect, the largest absolute phase offset valuescorresponds to the worst case absolute phase offset value and is theselected as the system offset value. In some aspects, processor 201 maybe configured to set a media buffer (e.g., ROM, RAM, flash memory,EEPROM) to prevent overflow for implementing the worst case absolutephase offset value as an offset in the processing node 200.

In an aspect, processor 201 may provide transmitter 205 with feedbackdata that includes the system offset value. In some aspects, transmitter205 may transmit the feedback data that includes the system offset valueso that AV master may receive transmitter, a report from processing node200 including the worst case absolute phase offset value and adjustingthe phase for one or more AV data packets based on the report. This maybeneficially adjust a system wide offset and reduce the amount of offsetapplied to each processing node.

In an aspect, processing node 200 may include decoder 202. Decoder 202may decode each of the AV data packets to extract a time referencemarker that is indexed to a real-time based time stamp (e.g., auniversal time stamp generated remotely, such as a PTP time stamp). Insome aspects, as depicted in FIG. 2, decoder 202 may be part ofprocessor 201. In some aspects, decoder 202 may include applicationspecific circuitry that is separate from processor 201.

PLL 203 is a phase lock loop that extracts the clock for the media fromthe time markers and determines a phase offset of the AV data signaldecoded by decoder 202 compared to the original AV data signal sent bytransceiver 114. In some aspects, processor 201 may include PLL 203 asdepicted in FIG. 2. In some aspects, PLL 203 may include applicationspecific circuitry that is separate from processor 201.

FIG. 3 is a signal diagram that illustrates broadcasting a time stampand distributing timing offset values. In a broadcast network having amaster timing component, shown as AV master 301, and a plurality ofdistribution nodes represented by distribution node 302, and a pluralityof processing nodes represented by processing node 303, time stamps andoffset delays may be distributed as follows. AV master 301, such as atransmitter at a broadcast production facility, may send a time stampbroadcast 321 periodically to all network nodes, such as distributionnode 302 and processing node 303. As shown, processing node 303 mayreceive the broadcast from distribution node 302. Each network node thenmay determine the offset delay measured at that node, and then sendindividual offset delay reports 322 back to the AV master 301. Forexample, path 304 measures AV data plus an additional delay of δ betweenAV master and distribution node 302. In turn, distribution node 302 mayreport back a delay of δ between AV master and distribution node 302 asindicated in path 308. Likewise, path 306 measures AV data plus anadditional delay of Δ between distribution node 302 and processing node303. In turn, processing node 303 may report back a delay of Δ betweendistribution node 302 and processing node 303 as indicated in path 312.

The AV master 301 may evaluate all individual offset delays throughoutthe network as received in the individual offset delay reports 322, anddetermine a system offset value based on a worst case offset delayvalue. The worst case offset delay value is applied to a line buffersetting assuring that any network device can manage it. In an aspect,the path with the largest delay, which corresponds to the worst caseabsolute phase offset value, may be path 308 and 312 that reports backas path 310 corresponding to delay (δ+Δ). In an aspect, the AV master301 may send a system offset broadcast 323 to all network nodes so thatline buffers may be set to a number of buffered lines. For example,based on the report that indicates that path 310 corresponding to delay(δ+Δ) is the worst case absolute phase offset value. AV master 301 maydetermine a system offset value of delayed (δ+Δ). In this instance, asdepicted in FIG. 3, the offset value at AV master 301−(δ+Δ). Thus, afterdelay, the offset value at distribution node 302 is−(Δ), whichsynchronizes the processing node 303 with no offset value.

FIG. 4 is a flowchart of a method 400 for precision timing of abroadcast network. In some aspects, the broadcast network is a systemfor timing synchronization of packetized audio video (AV) data in amedia network (e.g., media processing network 100) for phase locking anetwork node or receiver to an AV master, which is the source of the AVdata transmission, and for receivers/network nodes setting their linebuffers according to a system offset delay value. The system in thenetwork (e.g., media processing network) 100 may include transmittersuch as a processing node 128 and receiver such as AV master 301.

In an aspect, at block 404, the system for timing synchronizationreceives the AV data encoded with one or more time markers, wherein theone or more time markers are indexed to a precision time protocol (PTP)time stamp used as a time reference for a network. The one or more timemarkers may be indexed to a precision time protocol (PTP) time stampused as a time reference for the network. For example, prior totransmission AV master may encode each AV data packets with one or moretimes stamps. The “time stamp” may be a PTP time stamp which is indexedto a universal coordinated time (UTC) value, or any similar time stampbased on a real-time value. As such, each time stamp is based on anabsolute reference value. In addition, the time stamp may be distributedin the L2 ethernet header or in the L4 RTP signal header, as examples.For example, as depicted in FIG. 3, processing node 303 receives AV datafrom AV master 301 via path 304 and path 306.

In an aspect, at block 406, the system for timing synchronization locksphase of the AV data to align phase of the AV data based on the one ormore time markers encoded at the transmitter(e.g., AV master). That is,the receiver (e.g., processing node) receives the AV data and theencoded one or more time markers. In some instances, a controller at thereceiver may determine the absolute reference value of the time markerand provide these values to the PLL so that the receiver may advance ordelay the timing in order to lock the phase.

In an aspect, at block 408, the system for timing synchronizationdetermines one or more frequencies of the AV data based on the one ormore time markers. That is, a controller or processor at the receivermay be configured to determine the difference between one or more timemarkers in order to determine one or more frequencies of the of the AVdata. In some instances, the difference in time stamps in a single AVpacket may correspond to x nanoseconds which in turn may be converted tofrequency based on the bit rate.

In an optional aspect, at block 410, the system for timingsynchronization detects one or more phase offset values of the AV databased on absolute reference values of the one more time markers. Forexample, a controller at the receiver may determine the absolutereference value of the time marker and subtracting the largest absolutereference value from the smallest absolute reference value may yield aworst case offset value. In another example, ordering the absolutereference values of the time markers from largest to smallest providesone or more an indication of one or more phase offset values.

In an optional aspect, at block 412, the system for timingsynchronization detects one or more phase offset values for eachparticular media type of the AV data based on absolute reference valuesof the one or more time markers. That is, a controller at the receivermay determine the absolute reference value of the time marker andsubtracting the largest absolute reference value of a particular type ofmedia (e.g., audio only) from the smallest absolute reference value of aparticular type of media (e.g., audio only) may yield a worst caseoffset value for a particular media type (e.g., audio only). In anotherexample, ordering the absolute reference values of the time markers fromlargest to smallest for each particular type of media (e.g., audio only)provides one or more an indication of one or more phase offset valuesfor a particular media type (e.g., audio only). This is beneficial inthat separating by media type may better utilize resources since theoffset may be different for each media type (e.g., audio packet delaydiffers from video packet delay).

In an aspect, at block 414, the system for timing synchronizationdetermines a system offset value based on a worst case absolute phaseoffset value. Similar to block 410 and block 412, a controller at thereceiver may determine the absolute reference value of the time markerand subtracting the largest absolute reference value from the smallestabsolute reference value may yield a worst case offset value. This isdepicted in path 312 and path 310 (FIG. 3) that provide the largest timedifference of (Δ+δ), which corresponds to the worst case offset value.

In an aspect, at block 416, the system for timing synchronization sets amedia buffer to prevent overflow based on the system offset value. Thatis, given the magnitude of the worst case offset value, the controllerof the receiver allocates sufficient memory buffer space to accommodatethe synching and tuning based on the offset value. Sufficient bufferspace accommodates delaying AV data packet for synchronization andensuring that sufficient space is allocated prevents overflow whichcould resulting “skipping” or jumbled media when played.

FIG. 5 is a conceptual data flow diagram illustrating the data flowbetween different means/components in a media processing system fortiming synchronization 500. The AV master 501 may be a processing node128 and node 528 may be AV master 301 that are part of a mediaprocessing network 100. The AV master 501 includes TX receiver 502, TXcomputer readable medium/memory 516, TX processor/controller 508, codec504, TX timing module 506, and TX transmitter 514. TXprocessor/controller 508 further includes a TX determination component510 and TX adjusting component 512. The node 528 includes RX transmitter518, RX computer readable medium/memory 520, RX processor/controller522, RX timing module 530, decoder 532, RX receiver 534, and PLL 536. RXprocessor/controller 522 further includes a RX determination component524, RX detection component 526, and RX adjusting component 529. In oneaspect, at AV master 501, TX transmitter 514 is configured to distributethe AV data encoded with one or more time markers to a plurality ofprocessing nodes. The one or more time markers are indexed to aprecision time protocol (PTP) time stamp used as a time reference forthe network. In this configuration, at node 528, RX receiver 534 isconfigured to receive the AV data. In addition, PLL 536 is configuredlock phase of the AV data to align phase of the AV data at node 528 withthe AV data at AV master 501 based on the one or more time markersreceived in the AV data.

In configuration, at node 528, RX processor/controller 522,particularly, RX determination component 524 is configured to determineone or more frequencies of the AV data corresponding to the transmitterbased on the one or more time markers. In one optional configuration, atnode 528, RX processor/controller 522, particularly, RX detectioncomponent 526 is configured detect one or more phase offset values ofthe AV data based on absolute reference values of the one more timemarkers. In one optional configuration, at node 528, RXprocessor/controller 522, particularly, RX detection component 526 isconfigured to detect one or more phase offset values for each particularmedia type of the AV data based on absolute reference values of the oneor more time markers. In one configuration, at node 528, RXprocessor/controller 522, particularly, RX determination component 524is configured to determine a system offset value based on a worst caseabsolute phase offset value. In some configurations, RXprocessor/controller 522, particularly, RX determination component 524may be configured to provide the frequency and phase to RX timing module530, which in turn provides the offset value to decoder 532. Inaddition, RX timing module includes PLL 536 that assists in reducingjitter as well as phase alignment. Decoder 532 provides the synchedmedia content with an output to a display or other electronic device forconsumption. In such a configuration, at node 528, RXprocessor/controller 522, particularly, RX adjusting component 529 isconfigured to set a media buffer to prevent overflow based on the systemoffset value. In some instances the media buffer may be computerreadable medium/memory 520. In one configuration, at AV master 501, TXreceiver 502 is configured to receive a report (e.g., feedback data)from each of the processing nodes including the worst case absolutephase offset value. In such a configuration, at AV master 501, TXprocessor/controller 508, particularly, TX adjusting component 512 isconfigured to adjust the phase based on the report. In someconfigurations the system offset value is based on a number of videolines. As depicted in FIG. 5, TX processor/controller 508, particularly,TX determination component 510 may be configured to provide AV data tocodec 504, which in turn encodes AV data to TX timing module 506. Assuch, TX timing module 506 may encode time markers into the AV data. Inaddition, TX timing module includes PLL 507 that assists in reducingjitter as well as phase alignment. In some instances, the one or moretime markers are indexed to a precision time protocol (PTP) time stampused as a time reference for the network.

By way of example and without limitation, the aspects of the presentdisclosure are presented with reference to systems and methods used toconfigure various components of a video production system that may beused for production of television programming or at sports events. Thevarious concepts presented throughout this disclosure may be implementedacross a broad variety of imaging applications, including systems thatcapture and process video and/or still images, video conferencingsystems and so on. It is understood that the specific order or hierarchyof blocks in the processes/flowcharts disclosed is an illustration ofexemplary approaches. Based upon design preferences, it is understoodthat the specific order or hierarchy of blocks in theprocesses/flowcharts may be rearranged. Further, some blocks may becombined or omitted. The accompanying method claims present elements ofthe various blocks in a sample order, and are not meant to be limited tothe specific order or hierarchy presented.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” The word “exemplary” is used hereinto mean “serving as an example, instance, or illustration.” Any aspectdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects. Unless specifically statedotherwise, the term “some” refers to one or more. Combinations such as“at least one of A, B, or C,” “one or more of A, B, or C,” “at least oneof A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or anycombination thereof” include any combination of A, B, and/or C, and mayinclude multiples of A, multiples of B, or multiples of C. Specifically,combinations such as “at least one of A, B, or C,” “one or more of A, B,or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and“A, B, C, or any combination thereof” may be A only, B only, C only, Aand B, A and C, B and C, or A and B and C, where any such combinationsmay contain one or more member or members of A, B, or C. All structuraland functional equivalents to the elements of the various aspectsdescribed throughout this disclosure that are known or later come to beknown to those of ordinary skill in the art are expressly incorporatedherein by reference and are intended to be encompassed by the claims.Moreover, nothing disclosed herein is intended to be dedicated to thepublic regardless of whether such disclosure is explicitly recited inthe claims. The words “module,” “mechanism,” “element,” “device,” andthe like may not be a substitute for the word “means.” As such, no claimelement is to be construed under 35 U.S.C §112(f) unless the element isexpressly recited using the phrase “means for.”

What is claimed is:
 1. A method for timing synchronization of audiovideo (AV) data, comprising: receiving the AV data encoded with one ormore time markers, wherein the one or more time markers are indexed to aprecision time protocol (PTP) time stamp used as a time reference for anetwork; locking phase of the AV data to align phase of the AV databased on the one or more time markers; determining a system offset valuebased on a worst case absolute phase offset value of the AV data; andsetting a media buffer based on the system offset value to delay timingof the locking of the phase of the AV data to prevent overflow of the AVdata.
 2. The method of claim 1, further comprising determining one ormore frequencies of the AV data based on the one or more time markers.3. The method of claim 2, further comprising detecting one or more phaseoffset values of the AV data based on absolute reference values of theone more time markers to determine the worst case absolute phase offsetvalue.
 4. The method of claim 2, further comprising detecting one ormore phase offset values for each particular media type of the AV databased on absolute reference values of the one or more time markers. 5.The method of claim 1, wherein the system offset value is based on anumber of video lines.
 6. A node for timing synchronization of audiovideo (AV) data, comprising: a receiver configured to receive the AVdata encoded with one or more time markers, wherein the one or more timemarkers are indexed to a precision time protocol (PTP) time stamp usedas a time reference for a network; a timing circuit configured to lockphase of the AV data based on the one or more time markers; and aprocessor configured to: determine a system offset value based on aworst case absolute phase offset value of the AV data: and set a mediabuffer based on the system offset value to delay timing of the lockingof the phase of the AV data by the timing module to prevent overflow ofthe AV data.
 7. The node of claim 6, wherein the processor is furtherconfigured to determine one or more frequencies of the AV data based onthe one or more time markers.
 8. The node of claim 7, wherein theprocessor is further configured to detect one or more phase offsetvalues of the AV data based on absolute reference values of the one moretime markers to determine the worst case absolute phase offset value. 9.The node of claim 7, wherein the processor is further configured todetect one or more phase offset values for each particular media type ofthe AV data based on absolute reference values of the one more timemarkers.
 10. The node of claim 6, wherein the system offset value isbased on a number of video lines.
 11. A non-transitory computer-readablemedium storing computer executable code for timing synchronization ofreceived audio video (AV) data, the computer readable media comprisingcode to: receive the AV data encoded with one or more time markers thatare indexed to a precision time protocol (PTP) time stamp used as a timereference for a network; lock phase of the AV data to align phase of theAV based on the one or more time markers; determine a system offsetvalue based on a worst case absolute phase offset value of the AV data;and set a media buffer based on the system offset value to delay timingof the locking of the phase of the AV data to prevent overflow of the AVdata.
 12. The non-transitory computer-readable medium of claim 11,further comprising code to determine one or more frequencies of the AVdata corresponding to the transmitter based on the one or more timemarkers.
 13. The non-transitory computer-readable medium of claim 12,further comprising code to detect one or more phase offset values of theAV data based on absolute reference values of the one more time markersto determine the worst case absolute phase offset value.
 14. Thenon-transitory computer-readable medium of claim 12, further comprisingcode to detect one or more phase offset values for each particular mediatype of the AV data based on absolute reference values of the one ormore time markers.
 15. The non-transitory computer-readable medium ofclaim 11, wherein the system offset value is based on a number of videolines.